Reese Witherspoon and Sofia Vergara are talented actors, but they’re not miracle workers. Hot Pursuit asks them to perform the cinematic equivalent of turning water into wine by wringing laughs out of 90 minutes of shrill screaming matches and goofy costumes. The movie ends with what’s essentially an admission of guilt: end credit outtakes, which are usually an indication that a comedy isn’t funny and knows it and is trying to hide that fact by sending the audience out of the theater with a couple desperate snickers and a warm feeling over the fact that the actors had a good time making the film. Good for them. Hot Pursuit is still a clunker.

Before that clunker reaches its destination, it drags Witherspoon and Vergara on a very tepid chase through Texas. The former plays Cooper, a straight-laced police officer raised by a hero cop to follow the rules no matter the circumstances. An accident early in her career got Cooper relegated to the evidence room, but she’s given a shot at redemption by her boss (Zodiac Killer John Carroll Lynch) when he needs a female officer to escort Daniella (Vergara), the wife of a cartel informant, to a court appearance in Dallas. Cooper’s dreams of proving herself are stymied, though, by the sudden appearance of several groups of assassins, who force the mismatched pair to go on the lam until Daniella can testify against a drug kingpin.

At least that’s what the screenplay by David Feeney and John Quaintance wants viewers to believe. But the reasons Cooper and Daniella go on the run could probably be cleared up with a brief phone call, so the film struggles mightily and clumsily to ensure that doesn’t happen. First Cooper loses her radio, then Daniella loses her phone. Then their car randomly overheats, they lose another phone, and their stalled car is conveniently struck by an out-of-control truck. The sheer absurdity of all this chaos is laughable, but it’s not particularly funny. At least when their car gets hit, all the cocaine that happened to be hidden inside flies everywhere, and onto Reese Witherspoon, who gets to act like she’s high for a couple minutes.

Most of Hot Pursuit’s comedy is pitched at that level; give Witherspoon and Vergara something vaguely wacky to do, and let ’em riff. At one point, they have to hide in a deerskin to evade police; in another they have to make out with each other to seduce a redneck (Jim Gaffigan) who found them on his property. Admittedly, neither star proves herself to be a master of improvisation, but Del Close would have had trouble finding the laughs in these schlocky premises. There are also gags about how Witherspoon is short and Vergara is in her 40s, and also a running joke about Witherspoon’s mustache, which supposedly makes her look like a man. But Witherspoon doesn’t have a mustache or look like a man (at least until she deliberately dresses like one in another sad sequence), so, uh, tee hee?

Cooper’s male colleagues repeatedly insult her because women, at least in their sexist brains, are just not cut out for police work. Like The Heat before it and Spy a little later this summer, Hot Pursuit tries to carve out a space for the fairer sex in the typically man-dominated genre of action comedies — in part by making that struggle for recognition one of its subplots. The Heat and Spy, though, were funny comedies and credible action flicks. Hot Pursuit is neither. Director Anne Fletcher (Step UpThe Proposal) doesn’t bring any excitement to the chases, and the big fight between Cooper and Daniella is a huge letdown; in between, the jokes never deliver more than a chuckle or two. Cooper’s bro buddies might underestimate Witherspoon and Vergara, but the problem with Hot Pursuit isn’t that these women are unworthy of headlining their own action comedy. It’s that Hot Pursuit is unworthy of them.